Radio receiving system



Jan. 18 1927. 1,614,458

o. E. CURTIS RADIO RECEIVING SYSTEM Filed May 31. 1923 will! %g ATTORNEY Patented Jan. 18, 1927.

UNITED STATES OTTO E. CURTIS, 0F PITTSFORD, NEW YORK.

RADIO RECEIVING SYSTEM.

Application filed May 31,

My invention relates to a radio system for receiving radio signals, including telephonic signals, and more particularly to an audion system for indoor receiving.

The object of the invention is to provide a simple and efiicient receiving system which does not require an aerial, and which can, therefore, be quickly and easily installed indoors.

I have illustrated a preferred embodiment of the invention in the accompanying drawing, which is a diagram showing the relation of the various parts, and in which there appears an audion having an incandescent lamp filament 1, a grid 2, a plate 3, a battery 1, a resistance 5 controlling the current to the filament 1, a grid leak and condenser 6, a coupler comprising coils 7 and 15, a receiver 8, battery 9 and a variable condenser 10. The system is connected directly to ground by means of aconductor 11 connecting with the system intermediate the main inductance of the coupler, and the grid 2 of the audion. The coils 7 and 15 of the coupler are located in the ouput and input circuits 13 and 12 respectively, so as to produce a regenerative effect.

15 designates the main inductance in the circuit 12, and forming part of the coupler already referred to, and let is a conductor leading from conductor 12 to the lower end of conductor 11 and ground, theconductor 14 including inductance 16, variable condenser 17 and switch 18, and I have discovered that best results are obtained by connecting one ground lead to the stator of its condenser, and the other ground lead to the rotor of its condenser. It has also been determined that the inductance 16 can be omitted under some conditions, although the greatest efliciency and most satisfactory results are secured with the inductance 16 in the circuit. If preferred, the invention may be carried out successfully by connecting conductors 11 and 14 to ground through independent ter 1923. Serial No. 642,597.

minals instead of through a common terminal, although the latter arrangement is usually the more convenient.

The characteristic feature of the invention resides in connecting both ends of the main inductance to a common ground terminal, one lead connecting from the grid terminal of the inductance through a variable condenser to ground, and the other lead connecting from the filament terminal of the main inductance through an inductance and variable condenser, or condenser alone, to the same ground terminal.

I claim:

1. A radio receiving system adapted for use indoors without use of an antenna or outdoor connection and comprising an audion including a grid and filament terminals, a coupler, an input circuit consisting of a loop that comprises two branches and is grounded through a relatively short common conductor, one branch of said loop extending from ground to a point intermediate the coupler and the grid and the other branch of said loop extending from ground to a point intermediate the coupler and filment, and a condenser in each branch of the loop.

2. A radio receiving system adapted for use indoors without use of an antenna or outdoor connection and comprising an audion including a grid and filament terminals, a coupler, an input circuit consisting of a loop that comprises two branches and is grounded through a relatively short common conductor, one branch of said loop extending from ground to a point intermediate the coupler and the grid and the other branch of said loop extending from ground to a point intermediatethe coupler and filament, a condenser in each branch of the loop, and an inductance in the filament side of the loop.

In witness whereof, I have hereunto signed my name.

. OTTO E. CUR-TIS. 

